Systems and methods for multi-modal and non-invasive stimulation of the nervous system

ABSTRACT

Systems and methods are provided to combine multiple stimulation modalities to significantly increase the effectiveness of non-invasive stimulation. Multiple sensor and stimulation devices and modalities can be combined into a single, compact unit that minimizes the need for additional sensors or stimulation devices. The system features several subunits, referred to as sensory and stimulation devices (SSD), that are integrated into a headphone setup. The system is controlled by a centralized controller that communicates with all of the SSDs and with an external computer system that delivers learning material synchronized with the delivery of stimulations and the collection of user responses based on physiological signals.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/342,096, entitled “Devices and Methods for Multi-Modal Non-InvasiveStimulation of the Autonomous and Central Nervous System” and filed onMay 26, 2016, which application is hereby incorporated by reference inits entirety.

BACKGROUND

The present application relates to systems and methods for multi-modaland non-invasive stimulation of the autonomous and central nervoussystem. More specifically, the present application relates to methodsand apparatus for multi-modal augmentation of neural plasticity of thenervous system and modification of the psycho-physiological state of theuser.

Electrical stimulation can be used to stimulate brain and nervous systemactivity for many different purposes. For example, electricalstimulation can be used to attempt to restore memory, increase cognitivefunction, modify psychophysiological state and for therapeutic purposes.The electrical stimulation can be applied through invasive andnon-invasive techniques. Typically, non-invasive techniques are used forthe convenience of the patient undergoing the electrical stimulation.Non-invasive techniques can typically involve the placement ofelectrodes near one or more nerves and/or the brain of the patient. Theelectrodes can then be used to apply a constant current to the nervesand/or brain in order to change the activity of the nerves and/or brainof the patient to get a desired response. The electrodes may also beused to apply a spatio-temporal activation pattern to the nerves and/orbrain of the patient in order to target specific nerves or regions ofthe brain to obtain a specific response.

When electrical stimulation is being used on a patient, other forms ofstimulation (e.g., visual stimulation or audible stimulation) are nottypically used or require the use of separate systems having separatecontrols that are not integrated with the electrical stimulationcontrols. In addition, when attempting to monitor the results ofelectrical stimulation (or other stimulations), separate monitoringsystems are required that can be cumbersome to the patient and requireintegration with the electrical stimulation system (or other systembeing used) in order to be able to identify potential responses tostimulation treatments.

SUMMARY

The present application generally pertains to combining multiplestimulation modalities to significantly increase the effectiveness ofnon-invasive stimulation. Multiple sensor and stimulation devices andmodalities can be combined into a single, compact unit that minimizesthe need for additional sensors or stimulation devices. The systemfeatures several subunits, referred to as sensory and stimulationdevices (SSD), that are integrated into a headphone setup. The system iscontrolled by a centralized controller that communicates with all of theSSDs and with an external computer system that delivers learningmaterial synchronized with the delivery of stimulation and collection ofphysiological signals.

Physiological signals can be used to assess the psychophysiologicalstate of the user and to modulate the user's psychophysiological statein order to optimize performance and/or reach an optimum state ofactivation of the autonomous and central nervous system for the givenapplication. When performing cognitive tasks a user requires an optimumarousal level. If the user's arousal level is too low or too high, theuser can have suboptimal cognitive performance. The arousal level of auser can be modified using breathing, audio stimulation (binauralbeats), vibration/bone conduction, photic stimulation, and non-invasivestimulation of branches of the vagus nerve. The arousal level of a usercan be assessed using a combination of: a) heart rate; b) heart ratevariability; c) respiration; d) respiratory sinus arrhythmia (i.e., achange of heart rate caused by respiration); e) galvanic skin response;f) brain electrical activity (e.g., electroencephalogram or EEG); g)pupil dilation; and/or h) vascular tone.

The system and combination of sensors can collect a maximum number ofsignals in a compact, unobtrusive unit and provide non-invasivestimulation to modulate the physiological state of the user. Optimumsensing and stimulation can be personalized to the user by combining themonitored signals and their features for the optimum assessment of theuser's state and stimulation. In one embodiment, a linear combination ofindividual parameters with weight factors for each feature can bedeveloped for each user. The training process for the system to assessindividual weight factors may include the subjective feeling/feedback ofthe user, as well as, objective measures of the cognitive performance ofthe user for the given task.

One advantage of the present application is that it can be used foraugmentation of cognition, recovery from traumatic brain injury orstroke, implementation of relaxation techniques, and for changing astate of consciousness.

Another advantage of the present application is that it can be used toimprove performance or change psychophysiological state of the user.

Other features and advantages of the present application will beapparent from the following more detailed description of the identifiedembodiments, taken in conjunction with the accompanying drawings whichshow, by way of example, the principles of the application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an embodiment of a multi-modal sensor andstimulation system.

FIG. 2 is a block diagram of an embodiment of a computing device of themulti-modal sensor and stimulation system of FIG. 1.

FIG. 3 is an embodiment of the user wearable device of the multi-modalsensor and stimulation system of FIG. 1.

FIG. 4 is an embodiment of the interior components of the headphone padof the user-wearable device of FIG. 3 relative to a user's ear.

FIG. 5A is a front view of an embodiment of the auricular SSD from FIG.4.

FIG. 5B is a side view of an embodiment of the auricular SSD from FIG.4.

FIG. 5C is a bottom view of an embodiment of the auricular SSD from FIG.4.

FIG. 6 is a block diagram of an embodiment of the control unit of FIG. 1with switched capacitor charge stimulation device.

FIG. 7 is a block diagram of an embodiment of the control unit of FIG. 1with a switched capacitor charge stimulation device with monitoring ofthe stimulation site.

Wherever possible, the same reference numbers are used throughout thedrawings to refer to the same or like parts.

DETAILED DESCRIPTION

The present application generally pertains to systems and methods forproviding several non-invasive stimulations to a user. The user canplace a device (e.g., headgear) on the user's head to receive thenon-invasive stimulations. The headgear can incorporate severaldifferent types of sensory and stimulation devices (SSDs) to provide thestimulations to the user. The different types of stimulation can includeelectrical stimulation, audio stimulation, photic stimulation, vibrationstimulation, olfactory stimulation and electromagnetic stimulation. Inaddition to providing stimulation to the user, the headgear can alsoinclude different sensors to measure different physiological parametersof the user. The sensors of the headgear can be used to measure theelectroencephalogram, the electrocardiogram, the photoplethysmogram, theelectrooculagram and/or the balistocardiograph of the user. Using themeasurements from the sensors, different physiological parameters of theuser can be determined such as brain activity, heart rate, bloodpressure, respiration rate, etc., to assess activity of central andautonomous nervous system.

The headgear worn by the user can include a top headband that ispositioned on top of the user's head and a front headband that ispositioned on the user's forehead. Each of the headbands can includeelectrical contacts that can be used to provide both electricalstimulation to the user and to measure physiological parameters of theuser. In addition, the headgear can include ear pads that are placedover the ears of the user. The ear pads can include both an ear budplaced in the ear and an SSD that is placed behind the ear. The ear budcan be used to provide audio stimulation to the user and can include astimulation device that can be used to provide electrical stimulation toa branch of the vagus nerve. The behind the ear SSD can includeelectrodes that are placed in contact with both the ear of the user andthe head of the user to provide both electrical stimulation to the userand to measure physiological parameters of the user. The behind the earSSD can also include a reference electrode that is in contact with theuser to provide a reference when measuring a physiological parameter ofa user. The behind the ear SSD can also include a pulse oximeter incontact with the lobule of the user and a vibration device that is incontact with the user to provide vibration stimulation to the user.

All of the sensors and stimulation devices of the head gear can be incommunication with a control unit. The control unit can be integratedinto the headgear or can be in a separate housing that is coupled to theheadgear. The control unit can send signals to and receive signals fromeach of the SSDs. The control unit can be in communication with acentral computer that controls the operation of the SSDs of the headgear. The central computer can provide instructions to the control unitto implement a variety of different stimulation sequences to the user,including instructions to provide targeted electrical stimulation tocertain areas of the brain. As the control unit receives the sensormeasurements from the SSDs, the control unit can provide themeasurements to the central computer. The central computer can thenevaluate the user's response to the stimulations and make adjustments tothe stimulations in order to achieve the desired results. Someadjustments that can be made to the stimulations include increasing ordecreasing the duration of the stimulation, increasing or decreasing themagnitude of the stimulation and/or adding or removing particular typesof stimulations.

In addition, the central computer can determine an arousal level of theuser, which can be used to optimize the user's cognitive learning. Thearousal level of the user can be determined with a combination ofphysiological parameters determined from the measurements of the sensorsin the headgear. The physiological parameters may or may not be weightedwhen determining arousal level for the user. If the physiologicalparameters are weighted, then each individual user may have a differentset of weights in order to determine that user's optimal arousal level.Further, the central computer can customize stimulation sequences foreach user in order to maximize the user's benefit from the treatment.

FIG. 1 shows a block diagram embodiment of a multi-modal sensor andstimulation system 100. The multi-modal sensor and stimulation system100 can include a user-wearable device 110 and a computing device 30coupled to the device 110. The device 110 can include one or moresensory and stimulation devices (SSDs) 10 that can provide differenttypes of stimulation to the user and measure the user's response to thedifferent stimulations. The SSDs 10 can be coupled to a control unit 20incorporated into the device 110. The control unit 20 can sendinstructions or signals to the SSDs 10 to control the operation of theSSDs 10. The control unit 20 can also receive data and/or signals fromthe SSDs 10 indicating the user's response to the stimulations. Thecontrol unit 20 can be coupled to the computing device 30 to receiveinstructions from the computing device 30 for the SSDs 10 and to providedata from the SSDs 10 to the computing device 30. In one embodiment, thecontrol unit 20 can communicate wirelessly (i.e., via electromagnetic oracoustic waves carrying a signal) with the computing device 30, but inother embodiments, it is possible for the control unit 20 to communicatewith the computing device 30 over a conductive medium (e.g., a wire),fiber, or otherwise.

FIG. 2 shows an embodiment of the computing device 30. The computingdevice 30 may be implemented as one or more general or special-purposecomputers, such as a laptop, hand-held (e.g., smartphone), desktop, ormainframe computer. The computing device 30 can include logic 32,referred to herein as “device logic,” for generally controlling theoperation of the computing device 30, including communicating with thecontrol unit 20. The computing device 30 also includes sensory andstimulation logic 34 to control the operation of the SSDs 10 and toprocess the data and information measured by the SSDs 10. The devicelogic 32 and the sensory and stimulation logic 34 can be implemented insoftware, hardware, firmware or any combination thereof. In thecomputing device 30 shown in FIG. 3, the device logic 32 and the sensoryand stimulation logic 34 are implemented in software and stored inmemory 36 of the computing device 30. Note that the device logic 32 andthe sensory and stimulation logic 34, when implemented in software, canbe stored and transported on any non-transitory computer-readable mediumfor use by or in connection with an instruction execution apparatus(e.g., a microprocessor) that can fetch and execute instructions. In thecontext of this application, a “computer-readable medium” can be anydevice, system or technique that can contain or store a computer programfor use by or in connection with an instruction execution apparatus.

The computing device 30 includes at least one conventional processingunit 38, which has processing hardware for executing instructions storedin memory 36. As an example, the processing unit 38 may include adigital signal processor or a central processing unit (CPU). Theprocessing unit 38 communicates to and drives the other elements withinthe computing device 30 via a local interface 42, which can include atleast one bus. Furthermore, an input interface 44, for example, akeyboard, a mouse, touchscreen, sensor or any other interface device orapparatus, can be used to input data from a user of the computing device30, and an output interface 46, for example, a printer, monitor, liquidcrystal display (LCD), or other display apparatus, can be used to outputdata to the user of the computing device 30. Further, a communicationinterface 48, such as at least one modem, may be used to communicatewith control unit 20.

FIG. 3 shows an embodiment of a user-wearable device 110. In oneembodiment, as shown in FIG. 3, the device 110 can be a type of headgearthat is worn on the head of the user. However, in other embodiments,different configurations of the device 110 can be used. The device 110can include headphone pads 112 that are placed in proximity to one orboth of the ears of the user. In one embodiment, the headphone pads 112can be circumaural pads that surround the ear. However, in otherembodiments, different configurations of the headphone pads 112 (e.g.,supra-aural) can also be used. The headphone pads 112 can incorporateone or both of speakers or earbuds 114 (that operate as an SSD), one ormore trigeminal SSDs 150 located near the temple between the ear andeye, and one or more auricular SSDs 116 located behind the ear. Thedevice 110 can include a top headband 118 with one or more electrodes120 that can provide electrical stimulation to the top of the head ofthe user and a front headband 122. In one embodiment, the front headband122 can include one or more photic SSDs 124 to provide photicstimulation to one or both of the user's eyes. In another embodiment,the photic SSDs 124 can be integrated into (or connected to) eyewearthat is worn by the user. In other embodiments, the front headband 122can include a virtual/augmented reality display or a screen/projectionunit. In still other embodiments, the front headband 122 can include oneor more electrodes (not shown) to provide electrical stimulation and/ora SSD (not shown) that can provide olfactory stimulation and monitoring.

FIG. 4 shows an embodiment of the interior components of the headphonepad 112 relative to a user's ear. As shown in FIG. 4, the auricular SSD116 can be located behind the ear lobe 130 of the user. In oneembodiment, the auricular SSD 116 can be a soft anatomically shapeddevice that can comfortably reside behind the ear of the user forprolonged periods of time. In another embodiment, the auricular SSD 116can have an arcuate shape to fit behind the ear of the user. As shown inFIGS. 5A-5C, the auricular SSD 116 can include a photoplethysmogram(PPG) sensor 132 (e.g., a pulse oximeter) to measure the PPG of theuser. The PPG represents blood volume pulse and can be used to measureor assess: a) heart rate (HR); b) heart rate variability (HRV); c)breathing rate (BR); and d) vascular tone using blood volume pulse orpulse travel time (PIT) as a latency of the PPG peak from the R peak inan electrocardiogram (ECG). The PPG sensor 132 can be implemented on thefront of the auricular SSD 116 to allow good contact with the lobule 131(see FIG. 2) of the ear, which is a location that can be used for PPGsensing.

The auricular SSD 116 can also include one or more electrical contacts(or electrodes) 134 for the monitoring of heart activity (e.g., an ECG),brain electrical activity (e.g., an electroencephalogram (EEG)), orgalvanic skin response (GSR). The electrodes 134 can be located on oneor both sides of the auricular SSD 116 to contact either a portion ofthe user's ear or a portion of the user's head (e.g., the temporal boneor the mastoid bone). An electrical contact (or electrode) 136 for theEEG reference can be located at the bottom of the auricular SSD 116 incontact with the mastoid bone or the lobule 131. A vibrator or speaker138 can be used to apply stimulation using bone conduction. Anaccelerometer 140 can be used for detection of a balistocardiograph(BCG) representing motion caused by the mechanical movement of theheart. In one embodiment, the delay between the BCG and the PPG is afunction of vascular tone/blood pressure and can be used to assess thearousal of the user.

The trigeminal SSD 150 can be attached to the exterior of the headphonepad 112 in one embodiment. However, in other embodiments, the trigeminalSSD 150 can be incorporated within the headphone pad 112 such that theheadphone pad 112 has an enlarged region enclosing the trigeminal SSD150. In still other embodiments, the trigeminal SSD 150 can beintegrated into the front headband 122. The trigeminal SSD 150 caninclude one or more electrodes that are positioned near the temple toprovide electrical stimulation to branches of the trigeminal nerve.

The earbud 114 can be a soft anatomically shaped device that cancomfortably reside in the ear with good contact with the cymba concharegion 133 of the ear. Acoustic stimulation can be delivered through aspeaker in the earbud 114 and the electrical stimulation of branches ofthe vagus nerve (VNS stimulation) can be delivered through electricalcontacts 142 of a stimulator that resides on soft extension of theearbud 114 designed to fit the anatomical shape of the cymba concharegion. While not shown in FIGS. 3 and 4, the control unit 20 can beincorporated in the headphone pad 112. However, in other embodiments,the control unit 20 may be incorporated into other portions of thedevice 110 (e.g., top headband 118).

Referring back to FIG. 3, the top headband 118 can integrate EEG sensorswith stimulation electrodes 120. In one embodiment, the placement of thesensors/stimulation electrodes 120 can follow standard EEG electrodeplacements, such as the international 10-20 system. The photic SSDs 124can be integrated into a separate band near the eyes of the user,integrated into the front headband 122, into eyeglasses or virtualreality goggles, or implemented as a modulation of the virtual oraugmented personal display. The photic SSDs 124 can provide cues for thepacing of the user's breathing or generate a Steady State Visual EvokedResponse (SSVER) from the user. The SSVER can be recorded with thebehind the ear SSD device 116 or by sensors in the front headband 122and used to assess the focused attention of the user. Olfactorystimulation can be implemented in a separate band close to the nose ofthe user or integrated into the other parts of the system, such as thefront headband 122 or a virtual reality display. Olfactory stimulationcan be controlled by the central computer 30 (see FIG. 1) to provide anemotional response as a “reward” for successful execution of a task tostrengthen learning by subliminal stimulation.

In one embodiment, magnetic field stimulation can be integrated into thedevice 110 by using coils instead of electrodes in one or more of thetop headband 118, the front headband 122 and the auricular SSD 116.

The device 110 can be used to detect one or more the following signalsfrom a user: an electroencephalogram (EEG); an electrooculagram (EOG); aphotoplethysmogram (PPG); and a balistocardiogram (BCG). In otherembodiments, the device 110 can be used to detect other signals from theuser. The detected signals can be provided to the control unit 20, whichcan then send the signals to the computing device 30 for processing bythe sensory and stimulation logic 34. The EEG can be detected withelectrodes in one or more of the top headband 118, the front headband122, and the auricular SSD 116. The EOG can be detected with the photicSSDs 124 and/or the front headband 122. The PPG can be detected with thePPG sensor 132. The BCG can be detected with accelerometer 140.

The device 110 and the computing device 30 can also be used to detectthe following physiological parameters from a user: brain electricalactivity using EEG; steady state evoked potentials (SSVEP) or steadystate evoked response (SSVER); eye movement and blinking using EOG;heart rate using ECG, PPG and/or BCG; heart rate variability (HRV) usingECG and/or PPG; vascular tone (i.e., the time delay between ECG/BCG andPPG for each heart beat); galvanic skin response (GSR); respiration rateand effort from PPG; respiratory sinus arrhythmia (i.e., the change ofheart rate or inter-beat intervals caused by respiration) usingrespiratory effort and RR intervals (i.e., the interval betweensuccessive Rs in the QRS complex of the ECG wave); blood pressureassessed using latency between ECG and PPG/BCG; and arousal as apersonalized weighted combination of the above parameters. In otherembodiments, the device 110 and the computing device 30 can be used todetect other physiological parameters from the user.

The sensory and stimulation logic 34 can provide signals or commands tothe control unit 20 of the device 110 for one or more of the followingstimulation types: electrical stimulation; audio stimulation; vibrationstimulation; photic stimulation; olfactory stimulation; andelectromagnetic field stimulation. In one embodiment, electromagneticfield stimulation can be integrated into the device 110 by using coilsinstead of electrodes in one or more of the top headband 118, the frontheadband 122 and the auricular SSD 116. Olfactory stimulation can beimplemented into the device 110 using a separate band close to the noseof the user or integrated into the other parts of the system, such asthe front headband 122 or a virtual reality display. Olfactorystimulation can be controlled by the central computer 30 (see FIG. 1) toprovide an emotional response as a “reward” for successful execution ofa task to strengthen learning by subliminal stimulation.

Photic stimulation may directly drive the visual cortex and createsteady state visual evoked potentials across the cortex that can bemeasured and analyzed using EEG electrodes in the top headband 118, thefront headband 122 and the auricular SSD 116. Vibration stimulation canprovide similar binaural beats stimulation or direct stimulation at thetarget frequency (e.g., at the frequency of targeted brain electricalactivity) using the vibrational device 138. Audio stimulation using theearbud 114 can use binaural beats to generate brain electrical activityat the precise frequency of the difference in frequencies between theleft and right ear.

The system 100 can implement electrical stimulation in the user as oneor more of current stimulation with a constant or variable current(e.g., transcranial direct current stimulation or tDCS), voltagestimulation with a constant voltage or charge stimulation. Charge basedstimulation can be used to create biological effects. A switchedcapacitor circuit is used to generate a precise charge and then apply itto selected electrodes for stimulation.

FIG. 6 shows of an embodiment of the control unit 20 with a switchedcapacitor charge stimulation circuit or stimulator 202 controlled by acontroller 204. The controller 204 can control the stimulator 202 inreal-time with a microprocessor 206 that communicates with the computingdevice 30 through interface 208. Microprocessor 206 controls switches ofa switched capacitor 210 to charge or discharge a capacitor C1. Duringcharging of the capacitor C1, the switched capacitor 210 is connected tothe digital to analog converter (DAC) 212 that generates an appropriatevoltage as instructed by the microprocessor 206. The voltage provided bythe DAC 212 can be either positive or negative, depending on therequired stimulation and the corresponding electrodes selected to applythe stimulation. The total charge (Q) on the capacitor C1 of theswitched capacitor 210 can be based on the output voltage (V) from theDAC 212 and the capacitance (C) of the capacitor C1. In one embodiment,the total charge Q for the capacitor C1 can be determined by multiplyingthe output voltage V by the capacitance C.

Before applying the stimulation, the microprocessor 206 can control afirst analog multiplexer 214 and a second analog multiplexer 216 toselect the electrodes to receive stimulation. In one embodiment, theelectrodes can be located in one or more of the top headband 118, thefront headband 122 and the auricular SSD 116. As shown in FIG. 6, thestimulator 202 has leads or connections for two electrodes, but thestimulator 202 may have leads or connections for one electrode or morethan two electrodes in other embodiments depending on the requirementsof the application and the number of outputs in the first and secondanalog multiplexers 214, 216.

FIG. 7 shows of an embodiment of the control unit 20 with a switchedcapacitor charge stimulation circuit or stimulator 202 with monitoringof the stimulation site. For some applications, stimulation can beenhanced by applying stimulation synchronized with the native activityof the nervous system. Thus, monitoring of the stimulation site may berequired in order to effectively perform the stimulation. Similar to theembodiment shown in FIG. 6, the stimulator 202 can be connected to thecontroller 204. However, in the embodiment of FIG. 7, the controller 204can include a signal conditioning circuit and analog to digitalconverter (ADC) 218 that is controlled by the microprocessor 206.

The signal conditioning circuit and ADC 218 can be connected to thestimulation side of the switched capacitor 210. By having the signalconditioning circuit and ADC 218 connected to the microprocessor 206,the microprocessor 206 can monitor the voltage between selectedelectrodes before and after a stimulation caused by connecting thecapacitor C1 to the corresponding electrodes. After reviewing thecorresponding voltage between the electrodes, the microprocessor 206 canadjust the charge provided to the switched capacitor 210 by the DAC 212in order to get a desired voltage between the electrodes.

In one embodiment, the system 100 can be used to create spatio-temporalactivation patterns of stimulation using software controlled stimulationwith charges of different intensity and polarity occurring at differenttimes and in different electrodes. The sensory and stimulation logic 34of computing device 30 can be used to create the spatio-temporalpatterns and to control the intensity, polarity and timing of thecharges provided by the stimulator 202 to the electrodes viacommunications with the controller 204. In addition, the sensory andstimulation logic 34 of computing device 30 can be used to providestimulations at specific times and specific locations in the device 110to obtain a better localization or focus of stimulation in the brain andnervous system. For example, specific electrodes in the top headband118, the front headband 122, the trigeminal SSD 150 and the auricularSSD 116 can be used to obtain a more focused stimulation of a region ofthe brain or nervous system.

In one embodiment, the system 100 can facilitate non-invasivestimulation with real-time monitoring of users for numerousapplications. For example, the possible applications for the system 100can include improving neural plasticity, improving cognitive performanceand providing relaxation techniques. To improve neural plasticity, thesystem 100 can provide a multi-modal, personalized combination ofstimulations combined with the delivery of new material, or newexercise. Some examples can include learning or rehabilitation, such asstroke or traumatic brain injury rehabilitation. Other applications alsoinclude treatment of the post-traumatic stress disorder desensitizationand reprocessing.

To improve cognitive performance, the system 100 can perform real-timemonitoring of signals that allows the real-time assessment of thearousal of the user, while providing different stimulation modalities tofacilitate modulation of arousal and overall psychophysiological stateby keeping the user “in the zone.”

To provide relaxation techniques, the system 100 can provide multimodalstimulation and physiological entrainment to create deeply relaxed statein the user. Binaural beat entrainment using natural sounds can becombined with photic stimulation to transition the brain electricalactivity of the user from Alpha to lower Alpha and Theta. Photicstimulation can create entrainment of breathing from the natural initialstate as detected using sensors to a relaxed, slower, and deeperbreathing. Optical stimulation can provide cues for breathing phases.The monitoring of the heart rate, heart rate variability, andrespiratory sinus arrhythmia can provide assessment of strain tooptimize basic physiology (breathing and heart rate) to the optimumlevel for the current state of the user. Closed loop control,entrainment, and stimulation by the system 100 can facilitatemodification of the physiological state of the user in minimum time.

In one embodiment, the system 100 can be used to implement an intervalperformance boost methodology. The interval performance boostmethodology can include a presentation phase, a learning phase and aconsolidation phase. The presentation phase combines stimulations for apersonalized optimization of the user's arousal to improve the user'scognitive performance and focused attention. The learning phase usesstimulation of memorization and repetition of the most importantconcepts to be learned by the user. The consolidation phase can create adeeply relaxed state with heightened awareness in the user by usingsensory withdrawal with brain entrainment to consolidate the newmaterial to be learned by the user.

In one embodiment, the multi-modal stimulations provided by the system100 may be user-configurable. A user of the system may select the modesof stimulation to be performed on the user and may select the amounts(or percentages) that the selected stimulations are applied to the user.Once the user has selected the modes and amounts of stimulation, thecomputing device 30 can develop a stimulation regimen for the user basedon the user-configured parameters. For example, a user may select toreceive electrical stimulation for 50% of the regimen, audio stimulationfor 30% of the regimen and photic stimulation for 20% of the regimenwhile foregoing other types of stimulation. In another embodiment,relative percentage of intensity of individual modalities might beselected according to user's preferences.

Although the figures herein may show a specific order of method steps,the order of the steps may differ from what is depicted. Also, two ormore steps may be performed concurrently or with partial concurrence.Variations in step performance can depend on the software and hardwaresystems chosen and on designer choice. All such variations are withinthe scope of the application. Software implementations could beaccomplished with standard programming techniques, with rule based logicand other logic to accomplish the various connection steps, processingsteps, comparison steps and decision steps.

It should be understood that the identified embodiments are offered byway of example only. Other substitutions, modifications, changes andomissions may be made in the design, operating conditions andarrangement of the embodiments without departing from the scope of thepresent application. Accordingly, the present application is not limitedto a particular embodiment, but extends to various modifications thatnevertheless fall within the scope of the application. It should also beunderstood that the phraseology and terminology employed herein is forthe purpose of description only and should not be regarded as limiting.

What is claimed is:
 1. A user-wearable device to provide stimulation tothe nervous system of a user, the device comprising: a headbandconfigured to be worn on a head of the user, the headband comprising atleast one electrode configured to provide electrical stimulation to theuser; and a headphone pad coupled to the headband and positioned inproximity to an ear of the user, the headphone pad comprising: a firstsensory and stimulation device (SSD) configured to provide a first typeof stimulation to the user; and a second SSD configured to provide asecond type of stimulation to the user, wherein the second type ofstimulation provided by the second SSD is different from the first typeof stimulation provided by the first SSD, the second SSD comprising asensor positioned in contact with the ear of the user to measure aphysiological parameter of the user, wherein the electrical stimulationprovided by the at least one electrode, the first type of stimulationprovided by the first SSD and the second type of stimulation provided bythe second SSD are adjustable by a control unit in response to themeasured physiological parameter of the user to obtain a preselectedarousal level from the user.
 2. The device of claim 1, wherein theheadband is a first headband and the device further comprises a secondheadband coupled to the first headband and configured to be worn on theforehead of the user, the second headband comprising a third SSDconfigured to provide a third type of stimulation to the user.
 3. Thedevice of claim 2, wherein the at least one electrode is an at least onefirst electrode, the third SSD comprises at least one of a photic SSD orat least one second electrode, the photic SSD coupled to the secondheadband and positioned in proximity to an eye of the user, the photicSSD configured to provide photic stimulation to the user, and the atleast one second electrode configured to provide electrical stimulationto the user.
 4. The device of claim 1, further comprising a third SSDpositioned in proximity to an eye of the user and configured to providephotic stimulation to the user.
 5. The device of claim 1, furthercomprising a computing device in communication with the control unit,the computing device configured to generate commands to the control unitto control operation of the at least one electrode, the first SSD andthe second SSD.
 6. The device of claim 1, wherein the first SSDcomprises an earbud positioned in proximity to the cymba concha regionof the ear, the earbud configured to provide acoustic stimulation to theuser.
 7. The device of claim 6, wherein the earbud comprises anextension portion having at least one electrical contact, the at leastone electrical contract configured to provide electrical stimulation toa branch of a vagus nerve.
 8. The device of claim 1, further comprisinga third SSD positioned in proximity to a nose of the user and configuredto provide olfactory stimulation to the user.
 9. The device of claim 1,wherein the at least one electrode is an at least one first electrode,the second SSD is positioned behind the ear of the user, the second SSDhaving a first side and a second side opposite the first side, thesecond SSD comprises at least one second electrode positioned on atleast one of the first side of the second SSD or the second side of thesecond SSD, the at least one second electrode configured to provideelectrical stimulation to the user.
 10. The device of claim 9, whereinthe at least one second electrode comprises a first plurality of secondelectrodes positioned on the first side of the second SSD for contactingthe ear of the user and a second plurality of second electrodespositioned on the second side of the second SSD for contacting a head ofthe user.
 11. The device of claim 9, wherein the headphone pad furthercomprises a third SSD positioned on an exterior portion of the headphonepad, the third SSD comprising at least one third electrode configured toprovide electrical stimulation to the user, wherein one or more of theat least one first electrode, the at least one second electrode and theat least one third electrode are controllable by the control unit toapply a spatio-temporal activation pattern to the user to focusstimulation on an area of a brain of the user.
 12. The device of claim9, wherein the at least one second electrode is configured to monitor atleast one of heart activity, brain electrical activity or galvanic skinresponse of the user.
 13. The device of claim 12, wherein the controlunit is configured to adjust the electrical stimulation provided by theat least one electrode, the first type of stimulation provided by thefirst SSD and the electrical stimulation provided by the at least onesecond electrode in response to the measured physiological parameter ofthe user and the monitored at least one of heart activity, brainelectrical activity or galvanic skin response.
 14. The device of claim1, wherein the at least one electrode is an at least one firstelectrode, the headphone pad further comprises a third SSD positioned onan exterior portion of the headphone pad, the third SSD comprising atleast one second electrode configured to provide electrical stimulationto the user.
 15. The device of claim 1, wherein the second SSD comprisesa vibrational device configured to apply stimulation using boneconduction.
 16. The device of claim 1, wherein the control unit isconfigured to adjust at least one of the electrical stimulation, thefirst type of stimulation or the second type of stimulation byincreasing or decreasing the duration of the corresponding stimulation.17. The device of claim 1, wherein the control unit is configured toadjust at least one of the electrical stimulation, the first type ofstimulation or the second type of stimulation by increasing ordecreasing the magnitude of the corresponding stimulation.
 18. Thedevice of claim 1, wherein the sensor is positioned to contact a lobuleof the ear of the user and configured to measure a photoplethysmogram ofthe user.
 19. A system to provide stimulation to the nervous system of auser, the system comprising: a headband configured to be worn on a headof the user, the headband comprising at least one electrode configuredto provide electrical stimulation to the user; a headphone pad coupledto the headband and positioned in proximity to an ear of the user, theheadphone pad comprising: a first sensory and stimulation device (SSD)configured to provide a first type of stimulation to the user; and asecond SSD configured to provide a second type of stimulation to theuser, wherein the second type of stimulation provided by the second SSDis different from the first type of stimulation provided by the firstSSD, the second SSD comprising a sensor positioned in contact with theear of the user to measure a physiological parameter of the user; and acontrol unit in communication with the at least one electrode, the firstSSD, and the second SSD, the control unit configured to adjust theelectrical stimulation provided by the at least one electrode, the firsttype of stimulation provided by the first SSD and the second type ofstimulation provided by the second SSD in response to the measuredphysiological parameter of the user to obtain a preselected arousallevel from the user.
 20. The system of claim 19, wherein the controlunit is configured to receive the measured physiological parameter ofthe user from the sensor, evaluate the measured physiological parameterto determine an arousal level of the user, and calculate an adjustmentto the electrical stimulation provided by the at least one electrode,the first type of stimulation provided by the first SSD and theelectrical stimulation provided by the at least one second electrodebased on the determined arousal level of the user.